Main content area

Flavonoid loaded nanoparticles as an effective measure to combat oxidative stress in Ribonuclease A

Roy, Pritam, Parveen, Sultana, Ghosh, Pooja, Ghatak, Kausani, Dasgupta, Swagata
Biochimie 2019 v.162 pp. 185-197
antioxidant activity, antioxidants, bacteria, chitosan, fluorescence, myricetin, nanoparticles, oxidants, oxidation, oxidative stress, polyphenols, quercetin, ribonucleases, solubility
Flavonoids like quercetin and myricetin serve as naturally occurring antioxidants but their bioactivity is limited due to low aqueous solubility and oxidation under physiological conditions. In this current study, the antioxidant activity of quercetin and myricetin loaded chitosan nanoparticles during the induced oxidation of Ribonuclease A (RNase A) has been compared with the corresponding free flavonoids. Oxidation of RNase A leads to intermolecular dityrosine (DT) bond formation which shows a characteristic fluorescence emission around 405 nm. Although both quercetin and myricetin loaded nanoparticles initially exhibit lower antioxidant property compared to the free flavonoids, however, with increase in oxidant concentration over time the DT fluorescence showed greater increase for free flavonoids in comparison to the nanoparticles. The polyphenol loaded nanoparticles are also found to be effective in preventing bacterial cell damage in oxidizing medium. The slow release of flavonoids from the nanoparticles is responsible for their prolonged antioxidant effect in the oxidizing medium unlike the free flavonoids which are exhausted almost completely in the initial phase.